1. Field of the Invention
The present invention relates to BB pellets, and more particularly, to an environmentally friendly biodegradable BB pellet, which can be degraded by the natural environment, whereby pollution upon organism and environment are prevented.
2. Description of the Related Art
Current BB pellets existing in the market are mostly made of 60 percent of stone powder and 40 percent of petrochemical plastic, wherein the petrochemical plastic is selected from polystyrene (PS) or polypropylene (PP), which is not degradable in the natural environment. As a result, if individual or groups engaging in sports activities of air-guns do not collect the BB pellets in the environment after finishing the activities, the BB pellets may easily pollute the environment or be hazardously eaten by wild birds. Therefore, BB pellets manufacturers began to develop biodegradable BB pellets for solving the hazardous pollution caused by petrochemical plastic BB pellets upon the environment.
Current biodegradable BB pellets are mainly produced in a manner of substituting the petrochemical plastic used by ordinary known BB pellets with biodegradable plastic, wherein the biodegradable plastic is mostly poly lactic acid (PLA). However, although poly lactic acid is a biodegradable material which can be degraded by the natural environment and prevent the pollutions upon organism and environment, the glass transition temperature (Tg) of the poly lactic acid is about 60 degree Celsius, and the poly lactic acid is highly rigid and brittle. As a result, when being fired, such BB pellets easily breaks or bursts and thus hurts surrounding people. In addition, the heat deflection temperature (HDT) of the poly lactic acid is about 58 to 60 degree Celsius, and the heat tolerance of the poly lactic acid is relatively low. As a result, such BB pellets may deform due to possible high temperature during the transportation, so a heat insulating device or refrigerated cabinet is needed for being transported, causing inconvenience.